LEITMOTIV (leading motive), term invented by Hans von Wolzogen (1848-1938), well-known Wagnerian analyst and commentator, as a convenient designation for the characteristic and constantly-recurring musical motives, also known sometimes as "representative themes," which play such an all-important part in Wagnerian opera and the development of which as a musical device constitutes one of Wagner's most important con tributions to the technique of opera. For though, as has often been pointed out, Wagner did not actually invent the principle of representative themes, which had been employed earlier in a rudimentary manner by Mozart, Weber and others, he developed it so enormously and utilized its possibilities with such con summate resourcefulness and skill as to make it practically a new thing and to produce in the result a kind of opera utterly different from any which had been known before.
And yet the principle in itself is so simple and, as it now seems, so obvious, that it might be thought surprising that it had never been turned to better account previously. But the average com poser might certainly well despair of employing the system with the amazing skill and resourcefulness displayed by Wagner. A whole treatise might indeed be written on the wonders of the leading motive system as it was developed by Wagner and in the case of which one knows not whether most to admire the felicity and expressiveness of the themes themselves or the wonderful manner in which they are subsequently developed.
Especially remarkable is the way in which they are modified and metamorphosed in correspondence with the varying require ments of the action and the development of the drama. An oft quoted instance from the "Ring" is the transformation which the simple joyous motive of "Siegfried's Horn Call"—ex. 1: But this is only one of countless examples which might be cited. Such an elementally simple theme, for instance, as that of the so-called "Bondage" motive from the Ring, consisting of two notes only, is made to undergo the most astonishing trans f ormations as the drama proceeds, while as one of innumerable other examples one may take the transformation of the bare and not particularly alluring theme of the "ring" itself—ex. 4:
into the gorgeous strains of the noble "Walhall" motive—ex. 5: Another typical instance, not so well known, of the ingenuity with which one theme is sometimes converted into another of a totally different character is afforded by the transformation of the simple and severe motive known variously as that of the "Spear" or the "Treaty"—ex. 6: the actual notes of the melodic outline being precisely the same but changed out of all recognition by the successive leaps to the octave, the alteration of the rhythm and the addition of the splendid harmonization.